It is conventionally disclosed in U.S. Pat. No. 6,764,963 that the channel mobility in the MOS structure can be improved by performing processing in hydrogen anneal or a wet atmosphere in the SiC semiconductor device in which face a set to a (11−20)-plane in the plane azimuth of a crystal face is used in a channel. Concretely, it is intended that the channel mobility is improved by selecting concentration or temperature of the hydrogen anneal or the wet atmosphere.
However, it is not still sufficient in the channel mobility obtained in a technique shown in U.S. Pat. No. 6,764,963, and it is expected to intend a further improvement of the channel mobility.